CN115248543A - Developing device and image forming apparatus including the same - Google Patents

Abstract

The invention provides a developing device and an image forming apparatus including the same. The developing device includes a developing container, a developer carrier, a regulating blade, and a blade sealing member. The developing container has an opening and a scraper opposing portion. The developer carrier has a developing region. The regulating blade has a fixing portion and a regulating portion. The blade seal member is bonded to a surface of the restriction portion on the upstream side in the rotation direction.

Description

Developing device and image forming apparatus including the same

Technical Field

The present invention relates to a developing device and an image forming apparatus including the same.

Background

An image forming apparatus such as a copier, a printer, a facsimile machine, and a multifunction machine using an electrophotographic method includes a developing device for developing an electrostatic latent image formed on an outer peripheral surface of an image carrier, that is, forming a toner image (developer image) on which the electrostatic latent image is developed.

The developing device includes a developing container and a developer carrier. The developing container contains a developer containing toner. The developing container has a container opening that opens to a downstream side of the developing container in a moving direction of the developing device inside the image forming apparatus when the developing device is attached to the image forming apparatus. The developer carrier is disposed in contact with or in proximity to the image carrier. The developer carrier carries developer (toner) in the developing container on an outer peripheral surface.

The developer carrier is disposed so as to overlap the container opening. A part of the developer carrier is exposed to the outside of the developing device through the container opening. The exposed portion of the developer carrier exposed from the container opening faces the image carrier, and forms a developing region. The developing region is a region for supplying the toner in the developing container to the image carrier.

As such a developing device, there is a developing device in which a regulating blade is disposed on the upstream side in the rotation direction of a developer carrier from a developing region. The regulating blade protrudes toward the outer peripheral surface of the developer carrier over the entire region in the direction along the rotation axis of the developer carrier. The tip of the regulating blade is in contact with or close to the outer peripheral surface of the developer carrier. The regulating blade regulates a layer thickness of the developer carried on the developer carrier.

The regulating blade is constituted by a fixing portion and a regulating portion formed as separate members. The fixing portion is a portion fixed to the developing container. The regulating portion regulates a layer thickness of the developer on the developer carrier. The fixing portion and the restricting portion are integrated by welding, bonding with an adhesive, or the like. In order to improve the rigidity and strength of the fixing portion, the thickness of the fixing portion is larger than that of the restricting portion. Therefore, the fixing portion to the regulating portion has a stepped shape, and the interval from the fixing portion to the developing container is smaller than the interval from the regulating portion to the developing container.

In such a developing device, a blade seal member is disposed between the regulating blade and the developing container. The blade sealing member blocks a gap between the regulating blade and the developing container to suppress outflow of the developer.

Disclosure of Invention

The invention provides a developing device capable of suppressing outflow of developer.

A developing device of a first structure of the present invention includes: a developing container having an opening and containing a developer containing toner therein; a developer carrier rotatably supported by the developing container, a part of an outer peripheral surface of the developer carrier on which the developer is carried having a developing region exposed from the opening and opposed to an image carrier, the toner being supplied to the image carrier in the developing region; and a regulating blade that is disposed on a rotational direction upstream side of the developer carrier with respect to the developing region and regulates a layer thickness of the developer carried by the developer carrier, wherein the developing container has a blade facing portion facing a surface on the rotational direction upstream side of the regulating blade, the developing device includes a blade seal member that is disposed between the regulating blade and the blade facing portion and closes a gap between the regulating blade and the blade facing portion, the regulating blade has a fixing portion facing the blade facing portion and fixed to the developing container, and a regulating portion that protrudes from the fixing portion toward the developer carrier, a gap between the regulating portion and the blade facing portion is larger than a gap between the fixing portion and the blade facing portion, and the blade seal member is bonded to the surface on the rotational direction upstream side of the regulating portion.

An image forming apparatus of a second configuration of the present invention includes: a device main body; the image carrier is arranged in the device main body and forms an electrostatic latent image on the outer peripheral surface; and a developing device configured as described above, which is detachably provided in the apparatus main body, and develops the electrostatic latent image into a toner image by bringing the developer carrier into contact with or close to the outer peripheral surface of the image carrier in a state where the developing device is mounted in the apparatus main body.

According to the first structure of the present invention, the blade seal member is bonded to the regulating portion. Therefore, even if the regulating blade is slightly inclined, a gap is less likely to be formed between the blade seal member and the regulating blade, and outflow of the developer can be suppressed. Even if the restoring force at the contact portion with the regulating portion is relatively small, a gap is hardly generated between the seal member and the regulating portion. Thus, the developer is difficult to flow out of the developing container.

Further, according to the second configuration of the present invention, it is possible to provide an image forming apparatus which can suppress outflow of the developer.

Drawings

Fig. 1 is a side cross-sectional view showing a schematic configuration of an image forming apparatus 1 according to the present invention.

Fig. 2 is a perspective view showing the entire developing device 33.

Fig. 3 is an enlarged sectional view of a peripheral portion of the photosensitive drum 31 and the developing device 33.

Fig. 4 is a plan view showing the developing device 33 in a state where the developing roller 37 (see fig. 2), the regulating blade 64 (see fig. 2), and the bushing cover 63 (see fig. 2) are removed from the developing container 36.

Fig. 5 isbase:Sub>A side sectional view of the developing device 33 taken along linebase:Sub>A-base:Sub>A shown in fig. 4.

Fig. 6 is a perspective view showing the blade seal member 67.

Fig. 7 is an enlarged partial view of the periphery of the end portion of the blade seal member 67 of the developing device 33 (the region surrounded by the circle B of the two-dot chain line in fig. 4).

Fig. 8 is a partially enlarged sectional view of the periphery of the regulating blade 64 (the region surrounded by the circle C of the two-dot chain line in fig. 3).

Detailed Description

Hereinafter, embodiments of the present invention will be described with reference to the drawings. Fig. 1 is a side cross-sectional view showing a schematic configuration of an image forming apparatus 1 according to the present invention. In fig. 1, the right side in the drawing is the front side of the image forming apparatus 1, and the left side in the drawing is the rear side of the image forming apparatus 1. In fig. 1, the upper side is referred to as the upper side of the image forming apparatus 1, and the lower side is referred to as the lower side of the image forming apparatus 1.

As shown in fig. 1, the image forming apparatus 1 (here, a black-and-white printer) includes a main body case 10 (apparatus main body), a paper feeding section 20, an image forming section 30, and a fixing section 40. The main body case 10 has a substantially rectangular parallelepiped frame structure. The paper feed unit 20 is housed in the main body case 10.

The main body casing 10 is provided with a front cover 11, a rear cover 12, a main body opening 15, and an upper cover 16. The front cover 11 is located on the front surface side of the main body casing 10. The rear cover 12 is located on the rear surface side of the main body housing 10. The main body opening 15 is formed above the main body casing 10. The upper cover 16 is provided on the upper surface of the main body case 10. The upper cover 16 can open and close the main body opening 15. By opening the upper cover 16, the inside of the main body casing 10 can be accessed through the main body opening 15.

A sheet discharge portion 13 for discharging a sheet (recording medium) after image formation is provided on the upper surface of the upper cover 16. A paper discharge port 14 is provided at an upper portion of the main body housing 10 so as to face the paper discharge portion 13 in the front-rear direction. The paper discharge port 14 is an opening communicating with the inside of the main body casing 10. In the following description, the term "sheet" refers to copy paper, coated paper, film copy paper, thick paper, postcards, tracing paper, and other sheet materials subjected to image forming processing.

In a state where the upper cover 16 is opened, the developing device 33 can enter and exit the main body casing 10 through the main body opening 15. In a state where the rear cover 12 is opened, the units (except the developing device 33) of the image forming section 30 and the fixing section 40 can enter and exit from the rear surface side of the main body casing 10.

The paper feed unit 20 includes a paper feed cassette 21. The sheet cassette 21 accommodates sheets for performing an image forming process. A part of the paper feed cassette 21 protrudes further forward from the front surface of the main body casing 10. The upper surface of the portion of the sheet cassette 21 housed in the main body case 10 is covered with a sheet cassette top plate 21U.

The sheet cassette 21 includes a sheet storage space for storing a sheet bundle, a lift plate for lifting the sheet bundle for sheet feeding, and the like. A paper ejection portion 21A is provided at an upper portion of the paper feed cassette 21 on the rear end side. The sheet feeding portion 21A is provided with a sheet feeding roller 21B, and the sheet feeding roller 21B feeds out the uppermost sheet of the sheet stack in the sheet feeding cassette 21 one by one.

The image forming unit 30 performs an image forming operation. The image forming operation is an operation of forming a toner image (developer image) on a sheet fed from the sheet feeding unit 20. The image forming unit 30 includes a photosensitive drum 31, and a charging unit 32, an exposure unit 35, a developing device 33, and a transfer roller 34 arranged around the photosensitive drum 31. The developer used for image formation is a non-magnetic one-component developer composed of only toner.

The photosensitive drum 31 (image carrier) includes a rotation shaft and an outer peripheral surface that rotates around the rotation shaft. The photosensitive drum 31 is formed of, for example, a known Organic Photo Conductor (OPC) and has a photosensitive layer formed of a charge generation layer, a charge transport layer, and the like on its outer circumferential surface. After the photosensitive layer is uniformly charged by a charging section 32 described later, an exposure section 35 irradiates light to form an electrostatic latent image with attenuated charge, and a developing device 33 carries a toner image on which the electrostatic latent image is developed.

The charging unit 32 (charging means) is disposed at a predetermined interval from the outer peripheral surface of the photosensitive drum 31, and uniformly charges the outer peripheral surface of the photosensitive drum 31 in a non-contact state. Specifically, the charging section 32 includes a charging line 321 and a gate electrode 322 (both refer to fig. 3). The charging wire 321 is a linear electrode extending in the rotation axis direction of the photosensitive drum 31, and generates corona discharge with the photosensitive drum 31. The gate electrode 322 is a grid-like electrode extending in the rotation axis direction of the photosensitive drum 31, and is disposed between the charging wire 321 and the photosensitive drum 31.

The charging section 32 generates corona discharge by passing a current of a predetermined current value through a charging wire 321, and uniformly charges the outer peripheral surface of the photosensitive drum 31 facing the grid electrode 322 at a predetermined surface potential by applying a predetermined voltage to the grid electrode 322.

The exposure section 35 (exposure device) has optical system devices such as a laser light source, a mirror, and a lens. The exposure portion 35 irradiates the outer peripheral surface of the photosensitive drum 31 with light modulated in accordance with image data from an external device such as a personal computer. As a result, the exposure unit 35 forms an electrostatic latent image corresponding to an image based on the image data on the outer peripheral surface of the photosensitive drum 31.

The transfer roller 34 has a rotation axis parallel to the width direction of the sheet and an outer peripheral surface facing the outer peripheral surface of the photosensitive drum 31. The transfer roller 34 is supported by the main body casing 10 so as to be rotatable about the rotation axis. The transfer roller 34 transfers the toner image carried on the outer peripheral surface of the photosensitive drum 31 to a sheet passing through a nip portion between the transfer roller 34 and the outer peripheral surface of the photosensitive drum 31. At the time of the transfer, a transfer voltage of an opposite polarity to the toner is applied to the transfer roller 34.

The fixing unit 40 is located downstream of the transfer roller 34 in the sheet conveying direction, and fixes the toner image transferred to the sheet. The fixing section 40 has a fixing roller 41 and a pressure roller 42. The fixing roller 41 includes a heat source therein, and heats the toner transferred to the sheet to a predetermined temperature. The pressure roller 42 is in pressure contact with the fixing roller 41, and a fixing nip portion is formed between the pressure roller 42 and the fixing roller 41. When the sheet having the toner image transferred thereon is conveyed to the fixing nip portion, the toner image is fixed to the sheet by the heating of the fixing roller 41 and the pressing of the pressure roller 42.

The main body casing 10 includes a main conveyance path 22F and an inverted conveyance path 22B. The main conveyance path 22F and the reversing conveyance path 22B convey a sheet. The main conveyance path 22F extends from the paper ejection portion 21A of the paper feed portion 20 to the paper discharge port 14 via the image forming portion 30 and the fixing portion 40. The inverting conveyance path 22B is a conveyance path that: when duplex printing is performed on a sheet, the sheet is returned to the upstream side of the image forming portion 30 in the main conveyance path 22F after single-sided printing.

The main conveyance path 22F extends from below toward above through a transfer nip portion formed by the photosensitive drum 31 and the transfer roller 34. Further, a registration roller pair 23 is disposed on the upstream side of the transfer nip portion in the main conveyance path 22F. The sheet is temporarily stopped by the registration roller pair 23, and after skew correction, is sent out to the transfer nip portion at a predetermined timing for image transfer. The main conveyance path 22F and the reversing conveyance path 22B are provided with a plurality of conveyance rollers for conveying a sheet. A pair of paper discharge rollers 24 is disposed near the paper discharge port 14.

The inverting conveyance path 22B is formed between the outer side surface of the inverting unit 25 and the inner surface of the rear cover 12 of the main body casing 10. Further, a transfer roller 34 and one of the registration roller pair 23 are mounted on the inner surface of the reversing unit 25. The rear cover 12 and the reversing unit 25 are respectively rotatable about the axis of a fulcrum portion 121 provided at the lower ends thereof. In the case where a jam occurs in the reversing conveyance path 22B, the rear cover 12 is opened. When a paper jam occurs in the main conveyance path 22F or when the unit of the photosensitive drum 31 and the developing device 33 are taken out to the outside, the reversing unit 25 is opened in addition to the rear cover 12.

As shown in fig. 1, guide rails 18 are formed on a pair of side surfaces 17 facing the sheet width direction (the paper surface direction in fig. 1) in the main body housing 10. The guide rail 18 has a track structure recessed in the width direction of the sheet. The guide rail 18 extends downward from the main body opening 15 to a mounting position P1 at which the developing device 33 is mounted to the main body casing 10.

Fig. 2 is a perspective view showing the entire developing device 33. Fig. 3 is an enlarged sectional view of a peripheral portion of the photosensitive drum 31 and the developing device 33. Fig. 4 is a plan view showing the developing device 33 in a state where the developing roller 37 (see fig. 2), the regulating blade 64 (see fig. 2), and the bushing cover 63 (see fig. 2) are removed from the developing container 36.

As shown in fig. 2, 3, and 4, the developing device 33 includes a developing container 36, a developing roller 37 (developer carrier), a supply roller 38, an agitating blade 333, and a guide portion 69.

The developing container 36 accommodates therein a non-magnetic one-component developer made of only toner, and also accommodates a developing roller 37, a supply roller 38, and the like. The developing container 36 has an agitation chamber 335, a container opening 60 (opening), and a liner cover 63. The stirring chamber 335 accommodates the developer in a stirred state.

Container opening 60 is located more rearward than stirring chamber 335 in the front-rear direction. The container opening 60 is a rectangular through hole that opens on the rear side (the side close to the photosensitive drum 31) of the developing container 36. The container opening 60 is formed to be elongated in the width direction (axial direction) of the developing device 33.

The developing roller 37 is provided inside the container opening 60 so as to overlap the container opening 60. A part of the outer peripheral surface of the developing roller 37 is exposed from the container opening 60 to the outside of the developing container 36. The developing roller 37 has a rotation shaft 39 extending in the width direction of the developing device 33 (the sheet width direction). The rotary shaft 39 is rotatably supported to the developing container 36. In other words, the developing roller 37 is supported by the developing container 36 via the rotary shaft 39, and can be rotated leftward (see fig. 3) about the rotary shaft 39. Hereinafter, the direction along the rotation shaft 39 will be referred to as "axial direction (rotation shaft direction)". Further, the rotation direction of the developing roller 37 about the rotation shaft 39 is referred to as "rotation direction".

The developing roller 37 can carry toner on the outer circumferential surface. When the developing device 33 is located at the mounting position P1, the portion of the developing roller 37 exposed from the container opening portion 60 comes into contact with, or comes close to and opposes the outer peripheral surface of the photosensitive drum 31. In this state, the developing roller 37 can supply the non-magnetic mono-component toner (developer) to the photosensitive drum 31.

The supply roller 38 is disposed between the developing roller 37 and the stirring blade 333. The supply roller 38 supplies a non-magnetic mono-component toner (developer) to the outer peripheral surface of the developing roller 37. The stirring blade 333 is provided in the stirring chamber 335, and stirs the developer in the stirring chamber 335.

The liner covers 63 are detachably attached to both ends of the developing container 36 in the sheet width direction. The liner cover 63 constitutes a side wall portion of the developing container 36. The liner cover 63 is formed with a plurality of through holes penetrating in the axial direction, into which the rotary shaft 39 of the developing roller 37 and the rotary shaft of the supply roller 38 are inserted, and the developing roller 37 and the supply roller 38 are rotatably supported.

The guide portion 69 is a cylindrical protrusion protruding from the bushing cover 63. The guide portion 69 can be engaged with the guide rail 18. By engaging the guide portion 69 with the guide rail 18, the developing device 33 can move along the guide rail 18 between the main body opening 15 and the mounting position P1.

The developing device 33 supplies toner to the outer peripheral surface of the photosensitive drum 31 in a state where it is attached to the main body casing 10 at the attachment position P1. This causes the electrostatic latent image formed on the outer peripheral surface of the photosensitive drum 31 to be developed (a toner image (visible image) on which the electrostatic latent image appears is formed).

As shown in fig. 2 and 4, a pressing member 43, a flat portion 62, a front seal member 65, a regulating scraper 64, and a scraper seal member 67 are provided around the container opening portion 60. The pressing members 43 are provided at both end portions in the axial direction of the developing roller 37. The flat portion 62 is located on the rear side (the side close to the photosensitive drum 31) of the container opening portion 60. The front seal member 65 is provided on the flat portion 62. The regulating blade 64 is fixed to the rear side end portion of the developing container 36. The blade seal member 67 is laminated on the back surface side of the regulating blade 64.

Fig. 5 isbase:Sub>A side sectional view of the developing device 33 taken along linebase:Sub>A-base:Sub>A shown in fig. 4. Fig. 6 is a perspective view showing the blade seal member 67. Fig. 7 is an enlarged partial view of the periphery of the end portion of the blade seal member 67 of the developing device 33 (the region surrounded by the circle B of the two-dot chain line in fig. 4). The blade seal member 67 shown in fig. 6 is shown in a state where the blade seal member 67 shown in fig. 4 is turned over in the front-rear direction, and the left-right direction in fig. 4 and 6 is opposite to each other.

The pressing members 43 are positioned to overlap both side ends of the container opening 60 in the axial direction (see fig. 2). As shown in fig. 5, the pressing member 43 has a pressing surface 44. The pressing surface 44 is a surface curved so as to be recessed toward the front side (the stirring chamber 335 side) along the outer peripheral surface of the developing roller 37. The pressing surface 44 faces the outer circumferential surface of the both end portions 66 of the developing roller 37 in the radial direction of the developing roller 37.

The pressing member 43 is formed to have a thickness larger than a gap between the outer peripheral surface of the developing roller 37 and the inner surface of the developing container 36. Thus, when the developing roller 37 is attached to the developing container 36, the pressing surface 44 contacts the outer peripheral surface of the developing roller 37, and presses the developing roller 37 in the radial direction of the developing roller 37. The pressing surface 44 presses the both end portions 66 by contacting them, thereby closing the gap between the both end portions 66 and the developing container 36, and suppressing the developer from flowing out from the inside of the developing container 36.

The pressing member 43 has a multilayer structure (here, a 2-layer structure) in which a plurality of sheet members are laminated in the radial direction of the developing roller 37. At least the sheet member closest to the developing roller 37 in the radial direction among the multi-layer sheet members is a sheet member of polytetrafluoroethylene (so-called teflon). The pressing surface 44 is formed on the surface of the sheet member. The other of the multi-layer sheet member is formed of urethane foam such as sponge.

Returning to fig. 2 and 3, flat portion 62 is a plane surface connected to a portion of the inner surface of developing container 36 located below developing roller 37. The flat portion 62 extends rearward (in a direction approaching the photosensitive drum 31) from the container opening 60. When the developing device 33 is located at the mounting position P1, the flat portion 62 is substantially horizontal.

The front seal member 65 is a rectangular sheet formed of a PET film or the like. The front seal member 65 is stacked above the flat portion 62, and is adhered to the developing container 36 with an adhesive or the like. The front seal member 65 is formed to be elongated in the axial direction. The front seal member 65 extends between both end portions 66 of the developing roller 37 in the axial direction.

Of both end edges of the front seal member 65 in the front-rear direction (direction orthogonal to the sheet width direction), an end edge on the side close to the developing roller 37 (supply roller 38) is in contact with the entire developer bearing region of the outer peripheral surface of the developing roller 37 in the axial direction. The front seal member 65 blocks the gap between the developing container 36 and the developing roller 37 by contact with the outer peripheral surface of the developing roller 37, and suppresses outflow of the developer in the developing container 36.

The front seal member 65 has a first shielding portion 19. The first shield portion 19 is erected in a surface direction of the front seal member 65 from an end edge of the developing roller 37 (supply roller 38) side out of both end edges in the front-rear direction (direction orthogonal to the sheet width direction). The first shielding portion 19 protrudes upward over the entire axial region of the end edge of the front seal member 65. The first shielding portion 19 has a square shape formed of sponge or the like. The first shielding portion 19 is bonded to the surface of the front seal member 65 with an adhesive or the like. The first shielding portion 19 keeps the developer slightly flowing out from the gap between the developing roller 37 and the developing container 36 from falling outside the developing device 33.

A plate-shaped second shielding portion 53 protruding upward is provided on the outer side of both end portions in the axial direction of the first shielding portion 19. The second shielding portion 53 is located at a position overlapping the pressing member 43 in the axial direction. The second shielding portion 53 is integrally formed with the bushing cover 63. In a state where the hub cover 63 is attached to the developing container 36, the second shielding portion 53 extends from the hub cover 63 in the axial direction so as to approach the first shielding portion 19.

Fig. 8 is a partially enlarged cross-sectional view of the periphery of the regulating blade 64 (the region surrounded by the circle C of the two-dot chain line in fig. 3).

As shown in fig. 8, the developing container 36 has a scraper opposing portion 45. The blade facing portion 45 is located at an upper portion of the opening edge of the container opening portion 60. The blade facing portion 45 faces a surface on the upstream side in the rotation direction of the regulating blade 64 (a surface forward in the front-rear direction). The scraper opposing portion 45 is formed flat in the axial direction.

The regulating blade 64 is a plate-like body (see fig. 2) formed in a rectangular shape elongated in the axial direction. The regulating blade 64 includes a fixing portion 46 and a regulating portion 47. The fixing portion 46 is a metal plate-like body having an L-shaped side view with a bent portion bent at substantially right angles. The fixing portion 46 is disposed to face the blade facing portion 45 in the rotation direction.

The restricting portion 47 is a metal rectangular plate-like body formed to be elongated in the axial direction. The upper end of the regulating portion 47 is laminated and welded to the surface on the downstream side (the photosensitive drum 31 side) in the rotational direction of the fixing portion 46. The restricting portion 47 protrudes toward the developing roller 37 from a lower end portion of the fixing portion 46 (an end portion of the fixing portion 46 closest to the developing roller 37 in the up-down direction).

The distal end portion of the regulating portion 47 in the protruding direction is arranged to contact the outer peripheral surface of the developing roller 37. The toner supplied to the developing roller 37 enters between the regulating portion 47 and the developing roller 37 with the rotation of the developing roller 37, and is carried on the developing roller 37 as a thin layer having a constant thickness while being frictionally charged.

As shown in fig. 8, the thickness of the restricting portion 47 (the dimension in the front-rear direction of fig. 8) is smaller than the thickness of the fixing portion 46. That is, the distance L2 in the thickness direction between the regulating portion 47 and the blade facing portion 45 is larger than the distance L1 in the thickness direction between the fixing portion 46 and the blade facing portion 45.

In the restricting blade 64, a through hole is formed in a laminated portion of the fixing portion 46 and the restricting portion 47 so as to penetrate the fixing portion 46 and the restricting portion 47 in the surface direction (thickness direction) of the fixing portion 46. The fixing portion 46 is fixed to the blade facing portion 45 by a connecting member 48 including a nut and a bolt inserted through the through hole.

As shown in fig. 8, a blade seal member 67 is provided between the regulating blade 64 and the developing container 36 in the rotational direction (direction orthogonal to the axial direction). The blade seal member 67 is disposed between the pair of pressing members 43 in the axial direction (see fig. 4). The blade seal member 67 is composed of a multilayer sheet including a first laminate 70 and a second laminate 71 laminated in the front-rear direction.

The first laminate 70 is formed in a square shape from sponge such as PORON. The first laminate 70 is formed to be elongated in the axial direction. Both end portions of the first laminate 70 in the axial direction are in pressure contact (contact and press) with the respective pressing members 43 (see fig. 4). The first laminate 70 is laminated on the surface of the fixing portion 46 and the regulating portion 47 on the side away from the photosensitive drum 31 (the surface on the upstream side in the rotation direction of the developing roller 37). A double-sided tape having an adhesive component on both sides is attached to a surface on the downstream side in the rotation direction (the rear side in the front-rear direction) of the first laminate 70. In other words, the double-sided tape is disposed between the first laminate 70 and the restriction portion 47. The first laminate 70 is bonded to the restriction portion 47 with the double-sided tape.

The first laminate 70 is pressed and compressed toward the scraper blade facing portion 45 by the fixing portion 46 and the regulating portion 47. The compression amount of the portion of the first laminated body 70 between the fixing portion 46 and the blade facing portion 45 is larger than the compression amount of the portion of the first laminated body 70 between the regulating portion 47 and the blade facing portion 45.

The first laminate 70 is formed to have a dimension in the vertical direction larger than a dimension in the thickness direction (front-rear direction) in a state before the arrangement (state before compression) and a state after the arrangement (state after compression) between the regulating blade 64 and the blade facing portion 45. In other words, a cross section orthogonal to the axial direction of the first laminate 70 is elongated in the up-down direction.

As shown in fig. 4 and 6, the first laminate 70 is composed of a first seal member 72 and a second seal member 73 which are arranged in the axial direction. A connecting portion 74 is formed at a portion of the first seal member 72 opposite to the second seal member 73.

The first seal member 72 is formed with a first protrusion 75 and a first recess 76. The first projecting portion 75 and the first recessed portion 76 are provided at the end portion located on the center side of the container opening portion 60 in the axial direction. The first protrusion 75 protrudes from an end of the first seal member 72 toward the axial direction. The first recess 76 is recessed from the tip of the first protruding portion 75 in the protruding direction toward the direction opposite to the protruding direction. The first protruding portion 75 and the first recessed portion 76 are adjacent in a direction orthogonal to the axial direction.

The second seal member 73 is formed with a second protrusion 77 and a second recess 78. The second projection 77 and the second recess 78 are provided at the end portions located on the center side of the container opening 60 in the axial direction. The second protrusion 77 protrudes from an end of the second seal member 73 toward the axial direction. The second recess 78 is recessed from the tip of the protruding direction of the second protruding portion 77 toward the direction opposite to the protruding direction. The second protrusion 77 and the second recess 78 are adjacent in a direction orthogonal to the axial direction.

The second protruding portion 77 overlaps the first recessed portion 76 in a direction (vertical direction) orthogonal to the axial direction. The length from the bottom of the second recess 78 to the tip of the second projection 77 is equal to or slightly less than the length from the bottom of the first recess 76 to the tip of the first projection 75. The first projection 75 is inserted into the second recess 78, and the second projection 77 is inserted into the first recess 76.

The connecting portion 74 is constituted by a first protruding portion 75, a first recessed portion 76, a second protruding portion 77, and a second recessed portion 78. The connection portion 74 joins the first seal member 72 and the second seal member 73 in the axial direction with an adhesive applied so as to block between the first protruding portion 75 and the second recessed portion 78 and to block between the first recessed portion 76 and the second protruding portion 77.

The second laminate 71 is a sheet material elongated in the axial direction. The second laminate 71 is formed of polyethylene terephthalate (PET). The rigidity of the second stacked body 71 is greater than that of the first stacked body 70. As shown in fig. 5 and 6, the second laminate 71 is laminated on the surface of the first laminate 70 opposite to the contact surface with the regulating blade 64 (the surface on the side away from the developing roller 37 in the front-rear direction). The second laminate 71 is bonded to the first laminate 70 with an adhesive or the like. The second stacked body 71 is stacked one on each of the first sealing member 72 and the second sealing member 73.

The axial length of the second stacked body 71 is shorter than the axial length of the blade seal member 67. Both end portions of the second stacked body 71 are located further inside than both end portions of the blade seal member 67 in the axial direction. In regions from both end portions of the blade seal member 67 in the axial direction to both end portions of the second stacked body 71, buffer portions 68 are formed in which the first stacked body 70 protrudes from the second stacked body 71.

The second stacked body 71 is provided with sealing side positioning projections 79 (positioning projections) which are positioned further inward than both end portions in the axial direction and are provided at axially symmetrical positions, respectively. The seal-side positioning projection 79 projects outward in the axial direction and the vertical direction from the edge of the blade seal member 67 (see fig. 7).

As shown in fig. 4 and 7, container-side positioning projections 80 are formed on both axial ends of the container opening 60. The container-side positioning projection 80 projects downward from a part of the inside of the developing container 36. The container-side positioning projection 80 has an opposing surface 81 formed on a surface thereof on a side close to the center of the container opening 60 in the axial direction. The opposing faces 81 of the container-side positioning projections 80 axially oppose each other sandwiching a portion of the scraper seal member 67.

The seal-side positioning projections 79 are located axially inside the respective container-side positioning projections 80. The sealing-side positioning projection 79 and the container-side positioning projection 80 are located at positions that overlap in the vertical direction. The seal-side positioning projection 79 is axially opposed to the container-side positioning projection 80. The second stacked body 71 is positioned in the axial direction by the seal side positioning projection 79 contacting the container side positioning projection 80.

As described above, the first laminate 70 is bonded to the restriction portion 47. Therefore, even if the regulating blade 64 is slightly inclined, a gap is less likely to be formed between the regulating portion 47 and the first laminate 70, and outflow of the developer can be suppressed.

Further, as described above, the compression amount of the portion of the first laminated body 70 between the fixing portion 46 and the blade facing portion 45 is larger than the compression amount of the portion of the first laminated body 70 between the regulating portion 47 and the blade facing portion 45. That is, the restoring force of the first laminate 70 at the portion between the regulating portion 47 and the blade facing portion 45 is smaller than the restoring force of the first laminate 70 at the portion between the fixing portion 46 and the blade facing portion 45. However, since the first laminate 70 is bonded to the regulating portion 47, a gap is less likely to be formed between the first laminate 70 and the regulating portion 47. Therefore, the developer is difficult to flow out from the developing container 36.

Therefore, it is possible to provide the developing device 33 capable of appropriately restricting the layer thickness of the developer of the developing roller 37 and suppressing the outflow of the developer.

Further, the first laminated body 70 is formed such that the dimension in the vertical direction of the first laminated body 70 in a compressed state is larger than the dimension in the thickness direction, and the first laminated body 70 is laminated on the fixing portion 46 and the regulating portion 47. That is, the first laminate 70 is in contact with the regulating blade 64 over a wide range in the up-down direction. Accordingly, the pressing force of the regulation blade 64 against the blade facing portion 45 can be suppressed to a level that stabilizes the regulation blade 64, and the inclination of the regulation blade 64 can be suppressed. Therefore, the outflow of the developer can be further appropriately suppressed, and it is possible to avoid a situation in which the regulating blade 64 is inclined and the layer thickness of the developer of the developing roller 37 cannot be appropriately regulated.

Further, as described above, the rigidity of the second laminated body 71 is greater than that of the first laminated body 70. Therefore, when the second laminate 71 is bonded to the first laminate 70, wrinkles and creases are less likely to occur in the second laminate 71, and a gap is less likely to occur between the second laminate 71 and the developing container 36 (blade facing portion 45).

Further, since the second laminated body 71 having a large rigidity is laminated and bonded to the first laminated body 70, the second laminated body 71 serves as a support, and the first laminated body 70 is difficult to bend. Therefore, when the first laminate 70 is bonded to the regulating blade 64 (the fixing portion 46 and the regulating portion 47), the bonding surface of the first laminate 70 to the regulating portion 47 can be prevented from being wrinkled or bent. Therefore, a gap is less likely to be formed between the first laminate 70 and the regulating portion 47, and outflow of the developer can be further appropriately suppressed.

Further, as described above, the second stacked body 71 is positioned by the contact of the sealing side positioning projection 79 with the opposing surface 81. Since the rigidity of the second stacked body 71 is greater than that of the first stacked body 70, the scraper seal member 67 is easily positioned by the contact of the seal-side positioning projection 79 with the opposing surface 81. Here, the second laminate 71 is laminated and bonded to the first laminate 70, and the first laminate 70, that is, the blade seal member 67 is positioned by the second laminate 71 being positioned. In this state, since the first laminate 70 is in pressure contact with the pressing member 43, the pressing member 43 closes the gap between the developing container 36 and the blade seal member 67 in the axial direction, and the developer outflow path can be closed.

As described above, the both end portions of the second laminated body 71 are located axially inward of the both end portions of the first laminated body 70, and the buffer portions 68 are formed in the first laminated body 70 from the both end portions of the second laminated body 71 to the both end portions of the first laminated body 70. Therefore, when the blade seal member 67 is positioned and both end portions of the first laminate 70 are in contact with the pressing member 43, the buffer portion 68 is compressed. Then, the compression rate of the portion (the buffer portion 68) of the first laminated body 70 that contacts the pressing member 43 is increased, and the sealability between the first laminated body 70 and the pressing member 43 can be improved. Therefore, the outflow of the developer can be more favorably suppressed.

Further, as described above, the first laminate 70 connects the first sealing member 72 and the second sealing member 73, which are separately formed, by the connection portion 74. The second stacked body 71 is stacked on the first sealing member 72 and the second sealing member 73, respectively. Therefore, when the scraper seal member 67 is disposed between the pair of pressing members 43 in the axial direction, the pressing members 43 can be disposed with play (gaps) between the first seal member 72 and the second seal member 73. In this state, the first seal member 72 and the second seal member 73 can be bonded with an adhesive at an interval that generates a predetermined contact pressure between the blade seal member 67 and the pressing member 43. This improves the assembling property and can suppress the manufacturing cost of the developing device 33.

Further, a first shielding portion 19 protruding upward is provided over the entire region of the end edge in the longitudinal direction of the front seal member 65. Therefore, even if the waste toner is accumulated around the container opening 60, when the developing device 33 is mounted to the main body housing 10 with the developing device 33 facing downward, the waste toner around the container opening 60 is blocked by the first shielding portion 19. Therefore, the waste toner can be suppressed from falling into the main body casing 10.

Therefore, it is possible to provide the developing device 33 capable of suppressing the developer from flowing out from the gap between the developing roller 37 and the developing container 36 and suppressing the developer from falling into the main body casing 10 from the periphery of the container opening portion 60 of the developing device 33.

Further, as described above, the second shielding portion 53 is located at a position overlapping the pressing member 43 in the axial direction. Therefore, even if the developer slightly flows out from the gap between the pressing member 43 and the developing roller 37, the second shielding portion 53 prevents the developer from flowing out to the outside of the developing container 36. Further, as described above, the second shielding portion 53 is formed integrally with the bushing cover 63. Therefore, the second shielding portion 53 is also positioned at a predetermined position while the bushing cover 63 is mounted. Therefore, the number of assembly steps can be reduced, and the manufacturing cost can be suppressed.

The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention. For example, although the black-and-white printer is described as an example of the image forming apparatus 1 in the above embodiment, the present invention can be applied to a tandem type or a rotary type color printer, for example. Further, the present invention can be applied to an image forming apparatus such as a copying machine, a facsimile machine, or a multifunction peripheral having functions of these.

Although the first laminate 70 is bonded to the restricting portion 47 as described above, it may be bonded to the fixing portion 46 in addition to this.

The blade seal member 67 may be configured to include only the first laminate 70 without including the second laminate 71. In this case, the surface of the first laminate 70 opposite to the regulating blade 64 may be bonded to the blade facing portion 45.

In the above embodiment, the first shielding portion 19 is formed of a sponge, but is not limited thereto and may be formed of another material. Further, the first shielding portion 19 may be configured as follows: which is formed integrally with the front seal member 65 and is bent to stand upward from the end edge of the front seal member 65. In this case, the number of parts of the front seal member 65 is reduced, and the manufacturing cost can be suppressed.

In the above embodiment, the developer is a non-magnetic one-component developer composed only of toner, but a two-component developer using toner and carrier may be used.

The present invention is applicable to an image forming apparatus including a developing device that performs development using a developer containing toner. By applying the present invention, an image forming apparatus capable of suppressing outflow of a developer can be provided.

Claims (8)

1. A developing device, comprising:

a developing container having an opening and containing a developer containing toner therein;

a developer carrier rotatably supported by the developing container, a part of an outer peripheral surface of the developer carrier on which the developer is carried having a developing region exposed from the opening and opposed to an image carrier, the toner being supplied to the image carrier in the developing region; and

a regulating blade arranged on the upstream side of the developing region in the rotation direction of the developer carrier and regulating a layer thickness of the developer carried by the developer carrier,

the developing device is characterized in that,

the developing container has a blade opposing portion opposing a surface on the upstream side in the rotational direction of the regulating blade,

the developing device includes a blade seal member disposed between the regulating blade and the blade opposing portion and closing a gap between the regulating blade and the blade opposing portion,

the regulating blade has a fixing portion that is opposed to the blade plate opposed portion and is fixed to the developing container, and a regulating portion that protrudes from the fixing portion toward the developer carrier, an interval between the regulating portion and the blade plate opposed portion being larger than an interval between the fixing portion and the blade plate opposed portion,

the blade seal member is bonded to a surface of the restriction portion on the upstream side in the rotation direction.

2. The developing device according to claim 1, wherein the blade sealing member has: a first laminate laminated on an opposing surface of the regulating blade, the opposing surface facing the blade seal member; and a second laminate laminated on a surface of the first laminate opposite to the regulating blade, the second laminate having a rigidity greater than that of the first laminate.

3. The developing device according to claim 2, wherein a surface of the second laminate on the upstream side in the rotation direction is bonded to the blade plate opposing portion.

4. The developing device according to claim 2 or 3, wherein both end portions of the second laminate in a rotation axis direction of the developer carrier are located more inside than both end portions of the first laminate in the rotation axis direction.

5. The developing device according to claim 2 or 3,

the first laminate has: a first sealing member and a second sealing member arranged in a rotation axis direction of the developer carrier; and a connection portion formed at an opposite portion of the first sealing member and the second sealing member,

the connecting part has: a first protruding portion that protrudes in the rotation axis direction from an end portion of the first seal member on the second seal member side toward the second seal member in the rotation axis direction; a first recess portion that is recessed from the end portion of the first seal member in a direction opposite to a protruding direction of the first protruding portion; a second protrusion portion that protrudes in the rotation axis direction from an end portion of the second seal member on the first seal member side in the rotation axis direction and is inserted into the first recess portion; and a second recess portion recessed from the end portion of the second seal member in a direction opposite to a protruding direction of the second protruding portion and into which the first protruding portion is inserted,

an adhesive is applied to at least a part of the space between the first protruding portion and the second recessed portion and the space between the first recessed portion and the second protruding portion, the first seal member and the second seal member are bonded, and the gap between the first seal member and the second seal member is closed by the adhesive.

6. The developing device according to claim 2 or 3, wherein the first laminate is a sponge.

7. The developing device according to claim 2 or 3, wherein the second laminate is a sheet material formed of polyethylene terephthalate.

8. An image forming apparatus, comprising:

a device main body;

an image carrier that is provided inside the apparatus main body and forms an electrostatic latent image on an outer peripheral surface; and

the developing device according to any one of claims 1 to 7, which is detachably provided inside the device main body, and in a state in which the developing device is mounted inside the device main body, the developer carrier is brought into contact with or close to an outer peripheral surface of the image carrier to develop the electrostatic latent image into a toner image.

Images